Blasting assembly



Nov. 10, 1959 WELSH, JR 2,911,910

BLASTING ASSEMBLY Filed Aug. 8, 1956 fir 1 INVENTOR RICHARD F. WELSH JR.

St ts Pater 2,911,910 Patented Nov. 10, 1959 BLASTING ASSEMBLY RichardF. Welsh, Jr., Martinsburg, W. Va., assigrror to E. I. du Pont deNeurons and Company, Wilmington, Del., a corporation of DelawareApplication August 8, 1956, Serial No. 602,784

2 Claims. (Cl. 102-24) The present invention relates to a blastingassembly particularly adapted for use in inaccessible locations. Moreparticularly the present invention relates to a blasting assembly whichmay be placed at an inaccessible location by means of a long pole.

Certain methods of low cost mining are based on the principle thatbroken rock or ore will flow by gravity down inclined passages or chuteshollowed out of virgin rock. By this method, ore can be transferredcheaply from the source area to another where it is loaded, eitherdirectly or indirectly, into mine cars. It is important in such anoperation that the maximum size of the particles to be transferred besmall enough relative to the minimum dimension of the passage so thatthe chunks of rock or ore will flow freely. Despite the fact that suchfactors are taken into account in the design of these passageways, theyfrequently do become blocked and cease to function. On occasion, rockjams will occur which bridge the passage and clog it. Sometimes, chunksof ore or rock, which are too large to enter the opening, become lodgedin the mouth of the passageway. When any of these conditions occur, itis necessary to remove the obstruction by blasting.

For many years the practice to relieve such obstructions was for theshot firer to make a hazardous approach to the jam from below in orderto secure an explosive charge in the proper position adjacent thereto.This charge, when detonated, broke up the constriction and permitted themining operation to continue. This was obviously a dangerous practicesince the safety of the operator during his ascent depended upon the jamholding fast.

In more recent times the practice has been for the operator to tie anexplosive charge to a long pole, insert the initiating means, i.e., -ablasting cap or a length of detonating fuse into the explosive charge,and wedge the pole in such a position that the charge is properlylocated near the jam. Since this technique does not require the operatorto remain under the rock jam for an extended period, it is a good dealsafer. The tying operation, however, is time consuming and inconvenient,and considerable skill is required to tie the explosive charge orcharges in such a manner that they do not become dislodged while thepole is being maneuvered into the desired position.

Accordingly, an object of the present invention is to provide a blastingassembly adapted for rapid and simple mounting on a pole. An additionalobject of the invention is the provision of a blasting assembly of thistype which is inexpensive, convenient, and safe to use. Other andadditional objects will become apparent as the invention is more fullyhereinafter described.

I have found that my objects are achieved when I provide a blastingassembly having a bag-like container which consists of a pair offlexible generally concentric, coextensive sleeves formed integral atone end only and remaining open at the other end. Such a container maybe conveniently formed by pulling a hollow sleeve of flexible materialthrough itself for one-half of its length. All or a portion of theannular space thus formed is then filled with a suitable blasting agentor explosive composition, such as dynamite or the like, and the ends ofthe sleeve are then gathered and tied to provide a pocket for thereception and retention of a positioning pole. By means of thepositioning pole, the package may be elevated to a lofty position anddisposed adjacent to a rock jam or similar constriction. To more fullyillustrate the invention, reference is now made to the accompanyingdrawings in which:

Figure 1 represents an elevational view of the sleeve which forms thecontainer for the assembly;

Figure 2 illustrates the sleeve of Figure 1 after it has been pulledthrough itself for one-half of its length;

Figure 3 is a top view of Figure 2;

Figure 4 is an elevational view of the sleeve of Figure 2 after it hasbeen loaded and tied;

Figure 5 is a bottom end view of the package of Figure 4;

Figure 6 shows the package of Figure 4 mounted on a positioning pole;and

Figure 7 is a cross-sectional View of the assembly of Figure 6 takenalong the line 7--7.

In the drawings, 1 represents a sleeve of flexible packaging materialsuch as cloth, burlap, polyethylene film, or the like. The sleeve isopen at both ends 2 and 3.

Figures 2 and 3 depict the sleeve 1 after it has been pulled throughitself for one-half of its length forming, in effect, a pair of flexiblegenerally concentric, coextensive sleeves formed integral at theirbottom end and remaining open on the top end. The ends 2 and 3 are nowon the same side and an annular space 4 is thus formed for reception ofa blasting composition. The latter may be a high explosive composition,such as dynamite or TNT, or it may be a less expensive blasting agent,such as any of the sensitized ammonium nitrate compositions which arewell-known in the blasting arts. As seen in Figure 3, the sleeve itselfis now of double thickness but is still hollow, as at 5.

The blasting composition is loaded into the annular space 4, preferably,but not necessarily, over about onehalf of its circumferential extent asillustrated at 9 in Figure 7. The ends 2 and 3 of the sleeve are thengathered and securely tied as by a wire or cord 6. The tie serves toseal the blasting composition 9 in the annular space 4 and to close offthe top of the center space 5 providing a pocket for reception andretention of a positioning pole. The pole 8 is inserted from the bottominto the mouth of the said pocket, indicated at 7 in Figure 5. Itpenetrates all the way up into the pocket until it abuts the bag tie 6which prevents it from passing any further. The assembly is now securelymounted on the pole and may be maneuvered without fear of its becomingeasily dislodged.

In use, the assembly is mounted on a pole as illustrated in Figure 6. Ablasting cap or other detonator may be tied to the neck of the packagewhen necessary. The package is then elevated to a position adjacent therock jam or constriction which is to be blasted and the blastingcomposition is detonated.

The particular material selected for the sleeve is not a criticalfeature of the present invention. Any flexible packaging material whichwill not easily tear or fracture under the conditions of use issuitable, such as heavy textile materials, plastic and rubber films, andthe like. The latter have the advantage of being substantiallyimpermeable to moisture. l have found that cotton cloth or burlaplaminated to a thin polyethylene film is especially suitable. Thepolyethylene (on the inside) serves 3 as a moisture barrier while theouter cloth or burlap provides additional strength.

In lieu of the bag tie 6, any other suitable closure may be usedprovided 'it is of sufficient strength to-resist-tearing-open when theassembly is loaded on a pole. For example, the ends fo the sleeves maybe taped or stapled shut instead of tied.

The positioning pole 8 may be wood or plastic or other similar material.In many cases it may be convenient to use a long branch or sapling whichis found in the area.

The precise nature and amount of the blasting composition used is not acritical feature ofrthe invention and will vary greatly, in practice,depending upon the material to be blasted. Generally speaking, anyreadily available commercial blasting composition is operable.

It will be readily apparent from the foregoing that the blastingassembly of the present invention is a cheap, safe,

W efiective assembly which may besecurely loaded on the end of a longpole for elevation and positioning at a lofty inaccessible point.

The invention has been clearly'disclosed in the foregoing specification.It will be expressly understood, however, that many variations in thedetails of construction, materials, assembly, and dimensions of partsmay be made without departing from the scope or spirit of the invention.I intend to be limited, therefore, only by the following claims:

I claim:

,1. A blasting assembly comprising a pair of flexible generallyconcentric, coextensive hollow sleeves formed integral at one end only,a blasting composition in the annular space formed by the walls of saidconcentric 4 sleeves, the open ends of the sleeves being bound securelyshut to close off the open upper end of said annular space containingthe blasting composition and to provide a pocket closed at the top andopen at the bottom for the reception and retention of a positioning polein the center of said concentric sleeves, and-a-positioning pole in saidpocket.

2. A blasting assembly comprising .a pair of flexible generallyconcentric, coextensive hollow sleeves formedintegral at one end only,'a blasting composition in the annular space formed by the walls of saidconcentric sleeves, the open ends of the sleeves being tied to close ofithe open upper end of said annular space containing the blastingcomposition and to provide a pocket closed at the top and open at thebottom for the reception and retention of a positioning pole in thecenter of said concentric sleeves, and a positioning pole in saidpocket.

References Cited in the file of this patent UNITED STATES PATENTS- GreatBritain Sept. 21, 1955

